Salicylic acid activates artemisinin biosynthesis in Artemisia annua L.

Abstract

This paper provides evidence that salicylic acid (SA) can activate artemisinin biosynthesis in Artemisia annua L. Exogenous application of SA to A. annua leaves was followed by a burst of reactive oxygen species (ROS) and the conversion of dihydroartemisinic acid into artemisinin. In the 24 h after application, SA application led to a gradual increase in the expression of the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) gene and a temporary peak in the expression of the amorpha-4,11-diene synthase (ADS) gene. However, the expression of the farnesyl diphosphate synthase (FDS) gene and the cytochrome P450 monooxygenase (CYP71AV1) gene showed little change. At 96 h after SA (1.0 mM) treatment, the concentration of artemisinin, artemisinic acid and dihydroartemisinic acid were 54, 127 and 72% higher than that of the control, respectively. Taken together, these results suggest that SA induces artemisinin biosynthesis in at least two ways: by increasing the conversion of dihydroartemisinic acid into artemisinin caused by the burst of ROS, and by up-regulating the expression of genes involved in artemisinin biosynthesis.

Effects of cobalt nanoparticles on artemisinin production and gene expression in Artemisia annua

“…The expression pattern of the SQS gene Elicitors induce genes involved in the biosynthetic pathway of secondary metabolites through their specific motifs in the promoter region. Salicylic acid and methyl jasmonate cause an increase in artemisinin production in A. annua through 2 TGACG motifs in the DBR2 gene promoter (Pu et al, 2009). In the DBR2 gene promoter there is a TGA box with a TGACGT/AA sequence for responding to auxin, a GARE element with a TAACAAA/G sequence for responding to gibberellins, and a Wun motif with a TCATTTCGAA sequence for responding to wounding.…”

Chitosan oligosaccharide and salicylic acid up-regulate gene expression differently in relation to the biosynthesis of artemisinin in Artemisia annua L.

“…2 and 3). Strangely, the effect of SA treatment is quite limited compared to a reported 50% promotion of the artemisinin concentration compared to controls after 10 mM SA treatment [14]. The effect of COS on large A. annua plants has not previously been reported in literature.…”

“…But most of these experiments were conducted on suspension or hairy root culture of A. annua and not on large growing plants as in the present study. Published results showed that ADS expression could be up-regulated by SA and methyl jasmonate (MJ), but with no response to DMSO; CPR could be up-regulated by ABA and miconazole, but showed no response to SA and MJ; CYP could be up-regulated by low concentrations of MJ (22 M), and DMSO, but showed no response to high concentration of MJ (100 M), SA and miconazole [10,[13][14][15][16]. The responses in expression of these three genes regulated by SA in our experiments were in agreement with published reports [13,14].…”

Molecular cloning, characterization, and promoter analysis of the isochorismate synthase (AaICS1) gene from Artemisia annua

“…Compared with controls, 1.0 mmol/L SA could increase the content of artemisinic acid, artemisinin, and dihydroartemisinic acid (Pu et al, 2009;Aftab et al, 2010;Guo et al, 2010). In addition, the artemisinin content of cell suspensions of A. annua treated with 20-50 mg/L (140-360 mmol/L) SA increased significantly, and the highest content was nearly 6-fold higher than that of controls (Baldi and Dixit, 2008).…”